This review provides an exploration of various catalytic pyrolysis techniques for bio-oil production, focusing on the effects of different pyrolysis methods (slow, fast, and flash pyrolysis) on bio-oil yield and composition. The review also discusses key factors influencing bio-oil production, including feedstock composition (cellulose, hemicellulose, and lignin), and the role of catalytic materials in enhancing yield and product selectivity. Three primary classes of catalysts—zeolites, carbonaceous materials, and metal oxides—are thoroughly examined, with a discussion on the differences between bulk catalysts and nanocatalysts. The paper highlights how these catalysts influence the formation of bio-oil components such as phenols, hydrocarbons, and oxygenated compounds. Furthermore, this review discusses recent advancements in catalyst design and modifications to optimize bio-oil production. This review provides the latest advancements in catalytic pyrolysis, emphasizing the correlation between catalyst properties and the resulting products. It aims to offer valuable insights into the future potential of catalytic pyrolysis for efficient biomass conversion and sustainable biofuel production.

The transition to sustainable energy storage solutions has driven significant interest in supercapacitors, which offer high power density, rapid charge–discharge capabilities, and exceptional cycle stability. Biomass-derived carbon nanomaterials have emerged as compelling candidates for supercapacitor electrodes due to their renewable origins, environmental compatibility, and cost-effectiveness. This study explores recent advancements in tailoring structural properties, for example in preparation methods and activation, which are essential for efficient charge storage and rapid ion transport. Attention is given to the dimensional configurations—spanning 0D to 3D structures—and their impact on electrochemical behaviors. This review outlines the challenges faced in scaling up and optimizing these materials for practical applications, alongside an outlook on future research directions. By bridging the gap between material design and application demands, this work contributes to advancing sustainable supercapacitor technologies for a greener energy future.

Uranium contamination in aquatic environments has raised increasing concerns because of its chemical toxicity and radioactivity, creating a persistent demand for efficient uranium sequestration and recovery technologies. Metal oxides have attracted considerable attention as materials for U(VI) sequestration owing to their chemical stability, tunable structures, and abundant reactive surface sites. This review systematically summarizes the fundamental chemistry and recent development of metal oxide-based materials for U(VI) sequestration from aqueous environments. The aqueous speciation of U(VI), surface chemistry of metal oxides, and major interfacial interactions governing uranium retention are first discussed. Representative materials, including iron oxides (FeOx), titanium oxides (TiO2), aluminum oxides (Al2O3), manganese oxides (MnOx), zirconium oxide (ZrO2), cerium oxide (CeO2), magnesium oxide (MgO), zinc oxide (ZnO), and mixed-metal oxide systems, are then reviewed with emphasis on their structural characteristics, uranium retention performance, modification strategies, and immobilization mechanisms. Current evidence demonstrates that U(VI) sequestration is strongly governed by the nature and accessibility of surface hydroxyl and metal–oxygen sites, which can be further regulated through structural modification, surface functionalization, defect engineering, and the construction of mixed-metal oxide systems. This review provides a systematic understanding of the relationships among oxide composition, surface structure, interfacial chemistry, and U(VI) sequestration behavior, offering guidance for the rational design of advanced metal oxide-based uranium sequestration materials.

Silicone rubber (SR) composites are candidate radiation-shielding materials, but their irradiation and annealing responses remain incompletely understood. Three predefined formulations containing boron carbide (B₄C), lead (Pb)/B₄C, or Pb were exposed to 100 kGy gamma irradiation in air and then annealed under nitrogen at 60–120 °C for 30–240 min. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectra retained the same characteristic band positions after irradiation, although their normalized band areas changed. Shore A hardness increased after irradiation in all formulations and remained above the corresponding pre-irradiation values after annealing. Electron paramagnetic resonance (EPR) spectra of the SR-B₄C formulation varied qualitatively with the annealing conditions, but absolute radical quantification and assignment of a unique reaction pathway were not possible. Because filler identity, filler loading, and silicone content varied simultaneously, differences among the formulations cannot be independently attributed to Pb, B₄C, or filler–matrix interactions. Based on one independently prepared parent specimen per formulation, these results describe irradiation and annealing responses in composites with micrometer-sized fillers. They may inform future comparisons with silicone-based shielding nanocomposites under matched compositions and treatment conditions.

Silica aerogel, a prototypical transparent nanoporous material with ultralow density and a widely tunable refractive index, is employed as a Cherenkov radiator for precision gamma-ray diagnostics in inertial confinement fusion experiments. However, its optical transmittance is highly sensitive to sol–gel chemistry. Here, silica aerogels were prepared from tetraethyl orthosilicate (TEOS), ethanol, water, and aqueous ammonia, followed by aging, solvent exchange, and supercritical drying. The study examined how catalyst, ethanol, and water concentrations regulate nanostructure and optical transmittance. Increasing ammonia content accelerated gelation, produced smaller framework particles, and enlarged the pore size and pore volume. These changes increased the transmittance at 550 nm from 79.6% for C1 to 84.9% for C7. Increasing ethanol concentration diluted TEOS and its hydrolysis products, extended gelation, and narrowed the particle-size distribution. The average particle size decreased from 21.79 to 17.01 nm, while the transmittance at 550 nm increased from 57.4% for E1 to 65.2% for E5. Water produced a non-monotonic response: insufficient water limited TEOS hydrolysis, whereas excessive water promoted structural heterogeneity. Intermediate water content provided the most favorable optical response. These findings define a process–structure–transmittance relationship in which formulation-dependent nanoscale network formation governs scattering losses and optical clarity.

Regulation of surface acidity is critical for steering reaction pathways in catalytic biomass conversion; however, the modulation of Lewis acidity in MXene-supported single-atom catalysts remains poorly understood. In this work, density functional theory calculations were performed to systematically investigate how surface terminations coupled with metal identity govern the Lewis acidity of single-atom sites on Ti₃C₂-based MXenes. Two representative terminations (-O and -OH) were considered, and various metal atoms were anchored to construct single-atom catalysts. Formation energies were evaluated to assess thermodynamic stability, while NH₃ adsorption energies were employed as a descriptor for Lewis acidity. The results reveal a pronounced termination-dependent modulation of acidity. Specifically, -OH termination disfavors single-atom stabilization, whereas -O termination ensures strong anchoring. Electronic structure analysis indicates that enhanced acidity originates from termination-induced electronic polarization and charge redistribution. This work establishes a structure–termination–acidity relationship and provides theoretical guidance for the rational design of MXene-based catalysts with tunable acidity.